Tag: botany

Quizzes (264) Questions (5276)

Questions Related to botany

Multiple choice botany nucleus and chromosome membrane bound organelles cell: size and differentiation microscopy

Which chromosome does not provide attachment site for spindle fibers?

  1. Acrocentric

  2. Metacentric

  3. Submeta centric

  4. Acentric
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
A chromosome in which the centromere is located quite near one end of the chromosome is called the acrocentric chromosome. Humans normally have five pairs of acrocentric chromosomes. Down syndrome is caused by an extra acrocentric chromosome (chromosome21). The acrocentric chromosome does not provide the attachment site for spindle fibers because centromere is located quite near one end of the chromosome.
So, the correct answer is 'Acrocentric'.
Multiple choice botany cell structure and organization membrane bound organelles cell: size and differentiation microscopy

Major constituent of latex is

  1. Alkaloid

  2. Rubber

  3. Pigments

  4. Salts
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Latex is a miliky, white emulsoin, composed with 30-40% rubber particles, 55-65% water, and small amounts of protein, sterol glycosides, resins, ash, and sugars. Natural rubber latex consists of particles of rubber hydrocarbon and nonrubber substances dispersed in an aqueous serum phase.


So the correct option is 'Rubber'.

Multiple choice botany cell structure and organization membrane bound organelles cell: size and differentiation microscopy

Name the part of the cell that stores vital substances.

  1. Mitochondria

  2. Vacuoles

  3. Plastid

  4. Golgi apparatus
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Mitochondria produces the energy currency, i.e., ATPs of the cell. Mitochondria take nutrients and convert them into energy molecules. This process is known as 'oxidative phosphorylation'. 
Plastids are present in plant cells, which synthesize and store important chemical compounds used by the cell. 
Golgi apparatus has the main function of modifying, sorting and packaging the proteins, which are synthesized by cells. Golgi bodies are also involved in the transport of lipid molecules across the cell. 

Vacuoles are storage bubbles found in animal and plant cells but bigger in plant cells. These are used for storage of food, water and many other vital substances. Thus, the correct answer is option B.

Multiple choice botany nucleus and chromosome membrane bound organelles cell: size and differentiation microscopy

Centromere is required for 

  1. Transcription

  2. Crossing over

  3. Cytoplasmic cleavage

  4. Movement of chromosomes towards poles
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The late prophase or metaphase chromosome has two similar threads or chromatids attached to each other by a narrow non stainable area called as centromere. The two parts of the chromatids on either side of centromere are called as arms. Centromeres bind to spindle fibres and help in movement of chromosomes to opposite poles.

Multiple choice botany cell structure and organization membrane bound organelles cell: size and differentiation microscopy

All of the following are functions of vacuole, except

  1. Maintains turgor of plant cells

  2. Provide aqueous environment for accumulation

  3. Play a role in growth by elongation of cells

  4. None of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A plant cell is characterised by a single large sap vacuole. They enclose sap or water with dissolved inorganic and organic substances. It is surrounded by a membrane called as tonoplast. Plant cell vacuole maintains osmotic pressure for turgidity and osmosis. They also store useful as well as waste substances. The growth in terms of increase in size depends on the elongation of the cell. For elongation of the cell, the protoplasm needs to push against cell wall from inside. The generation of pushing force depends on the osmotic pressure created by substances stored in central vacuole. Thus, the correct answer is option D.

Multiple choice botany nucleus and chromosome membrane bound organelles cell: size and differentiation microscopy

Kinetochore is the

  1. Fibrous granular structure within centromere.

  2. Protein disc near centromere

  3. Construction near chromosome end.

  4. End of chromosome.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
  • The kinetochore is a disc-shaped protein complex associated with the centromere of a chromosome during cell division, to which the microtubules of the spindle attach.
  • It forms on a chromatid during cell division.
  • Hence Kinetochore is the protein disc near the centromere.
  • So, the correct answer is 'Protein disc near centromere'.
Multiple choice botany nucleus and chromosome membrane bound organelles cell: size and differentiation microscopy

Which chromosome may lost during cell division?

  1. Giant chromosome

  2. Acentric chromosome

  3. Polycentric chromosome

  4. Telocentric chromosome
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Acentric chromosomes may be lost during cell division. An acentric fragment is a segment of a chromosome that lacks a centromere. Because the centromere is the point of attachment for the mitotic apparatus, acentric fragments are not evenly distributed to the daughter cells in cell division. As a result, one of the daughters will lack the acentric fragment. Lack of the acentric fragment in one of the daughter cells may have deleterious consequences, depending on the function of the DNA in this region of the chromosome

Multiple choice botany nucleus and chromosome membrane bound organelles cell: size and differentiation microscopy

If the centromere is sub-median and the two arms are unequal then the chromosome is called as

  1. Metacentric

  2. Submetacentric

  3. Acrocentric

  4. Telocentric
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
The centromere is the part of a chromosome that links sister chromatids. During mitosis, spindle fibers attach to the centromere via the kinetochore. 
Having the centromere near the center but not in the middle, so that one arm is shorter than the other is the property of a submetacentric chromosome.
Multiple choice botany cell structure and organization membrane bound organelles cell: size and differentiation microscopy

Tonoplast, the membrane of vacuole is a

  1. Living membrane

  2. Non-living membrane

  3. Impermeable

  4. Permeable and rigid
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Tonoplast or vacuolar membrane is the living membrane of the vacuole. It separates the vacuolar contents from the cell's cytoplasm. It helps the vacuole in maintaining the osmoregularity inside the cell.

Multiple choice botany cell structure and organization membrane bound organelles cell: size and differentiation microscopy

The vacuoles of plant cells

  1. Are filled with concentrated sugar and salt solution

  2. Are filled with dilute sugar and salt solution

  3. Are filled with cell sap

  4. Contain DNA, RNA and ribosomes
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Vacuoles are the membrane-bound organelle mostly found in the plant cell. It is the centrally located large storage bubble in the plant cells and filled with cell sap. They provide osmotic pressure and turgidity to the plant cell.